Live hangs while launching on OS X Lion or above

Symptom

Live gets unresponsive while launching on Mac OS 10.7 or above and takes 5-10 minutes to start.

No MIDI ports listed in Live's preferences → MIDI/Sync tab.

This error message might appear: "Company Support Dir not found"

Reason

The most prominent MIDI problem on Lion is caused by a Digidesign MIDI driver which is obviously not fully Lion compatible and causes all MIDI applications to hang while trying to initialize this driver. The system's Audio-MIDI-Setup is for example also affected (/Applications/Utilities/).